Genes encoding alpha and beta subunits of Na,K-ATPase are located on three different chromosomes in the mouse.

Abstract

We have made use of a panel of mouse-hamster somatic cell hybrids and restriction fragment length polymorphisms between two mouse species (Mus musculus and Mus spretus) to determine the chromosomal localization of genes encoding the .alpha. and .beta. subunits of the Na,K-ATPase (Na+,K+-activated ATP phosphohydrolase, EC 3.6.1.3). DNA probes for three distinct isoforms of the Na,K-ATPase .alpha. subunit mapped to three different mouse chromosomes: the .alpha.1 gene (Atpa-1) cosegregated with the Egf gene on chromosome 3; .alpha.2 (Atpa-2) with the cytochrome P-450PB gene family/coumarin hydroxylase locus on chromosome 7; .alpha.3 (Atpa-3) with the .alpha.-spectrin gene on chromosome 1. The Na,K-ATPase .beta.-subunit gene (Atpb) mapped to the same region of chromosome 1, but it was not tightly linked to the Atpa-3 gene. These results indicate that three isoforms of the Na,K-ATPase .alpha. subunit are encoded by three distinct genes. The dispersion of Na,K-ATPase genes suggests that their expression is not likely to be controlled by a common cis-acting regulatory element.